Backup gyros - which do you trust?

Big John wrote:

NDB approach is a non precision approach. Takes less Partial Panel
proficiency.

I'm quite aware of what is and isn't a precision approach.

What I don't understand is why you feel it's easier to fly an
NDB approach than an ILS approach partial-panel.

It seems to me that the NDB approach most strongly requires
accurate heading information. The course to be flown can not
be determined from the position of the ADF needle alone, it
can only be determined by comparing the ADF bearing to heading.
If your only source of heading info is a compass dancing wildly
as you bounce around, this gets "too interesting"

On an ILS or GPS approach, OTOH, it seems to me that the
course to be flown can be determined from the CDI position
alone. Needle left, turn left etc.

You can flop around on a NDB approach with it's higher minimums easier
on partial panel than you can on a precision ILS.

I don't understand this at all. Yes, the ILS becomes increasingly
sensitive as one descends closer to DH. But, if the wx is such
that the 800 ft minimums (or 600, or whatever they are) on an
NDB approach will get one in, one need not fly the ILS minimums
but can "flop around" on the less sensitive portion.

OTOH, if the wx is really crappy, all the flopping around on an
NDB you might care to do won't help you.

On instruments, it is hard enough with full panel to fly precision IFR
especially if the ILS beams have splits in them and the needles bounce
from stop to stop at minimums. We used to practice at Scramento and
never felt comfortable making the ILS approach there due to erratic
needle movements on final.

I've never experienced anything like this. Is this a Cat II or III
ILS?

Does that explain my feelings enough?

Not really I'm afraid. I must say the view that partial panel
NDB approachs are the most difficult seems to be held by many
of the local DEs, who will require a partial-panel NDB if there
is an ADF installed in the plane.

It's been so many years since I made a real partial panel approach.
It was a Radio Range (A/N) approach as I recall. Hit cone of silence,
turned to heading to field, let down to minimum altitude and flew the
time (minutes and seconds) to field. All the pilots wore those fancy
chronometers to time from cone of silence to field for instrument
approaches in those days )

Whew...is this the sort of approach being described in "Fate is
the Hunter"? How would you handle adjusting groundspeed vs. time?
Would you guesstimate your groundspeed from time between waypoints
before initiating descent, would someone on the ground give you
winds from which you'd calculate groundspeed? Would you adjust
power to always fly the same groundspeed, or adjust time? Sorry
for all the naive questions, but pilots who actually flew radio
range approaches are few and far between.

These days, if I time an approach where I could use DME to define
the MAP my instructor beats me with a board "timing is the least
accurate way to determine the MAP! Never depend upon time if
there's another way!" And he's not a young whippersnapper
either.

Appreciate your comment re practice instrument approaches.

Cheers,
Sydney